Self-oscillations and noise-induced flips of spontaneous electric field in microwave-induced zero resistance state

Experiments demonstrate that microwave illumination of a two-dimensional electron system in a perpendicular magnetic field can produce a state with vanishingly small dissipative response at low frequency. Such zero resistance state is attributed to the spontaneous formation of static electrical domains in an unstable uniform system with negative absolute conductivity. We show that the electrostatic coupling of this system to a weakly conducting doping layer leads to additional dynamic instabilities. In particular, the two-layer system can develop a limit cycle where the domain electric field periodically flips in time. The proposed model provides a natural explanation for quasiperiodic flips of internal spontaneous voltages observed in recent experiments. Copyright (C) EPLA, 2019